High speed transmission systems are used to connect discrete electrical circuits or devices. Voltage-mode (VM) drivers are used to convert a digital input signal to an analog output that can be transmitted over a low-impedance transmission line. It is important to match the output impedance of the VM drivers to the low impedance transmission line to reduce (e.g., minimize) reflections on the line. As such, it is desirable to be able to calibrate the output impedance of the VM driver to match the desired line impedance within acceptable limits. Some approaches in the related art involve splitting the VM driver into parallel slices, which are selectively enabled/disabled to achieve the desired output impedance. However, bringing on board many slices drives up power used by the predriver.
What is desired is a way of improving resolution of calibration while also reducing (e.g., minimizing) driver power consumption.
The above information disclosed in this Background section is for enhancement of understanding of the invention, and therefore it may contain information that does not form prior art that is already known to a person of ordinary skill in the art.